Bending machine

ABSTRACT

A bending machine having a mandrel carrier, two axles passing through the carrier on a diameter thereof and mandrels mounted on the axles, there being a space between the closest points of the mandrels for the workpiece to pass through. Journals in a fixed frame are provided for the axles so that the carrier can be rotated about the axis of either axle. The carrier is provided with sprocket teeth about its periphery, and is rotated by a chain passing around the sprocket to form a shape generally like a U. The ends of the chain are attached to drive rods which are hydraulically moved to pull the chain and rotate the carrier in either direction. The journals are arcuate and open away from the drive rods, the action of the rods and chain being in a direction to keep one axle in continuous bearing contact with its associated journal. Guide sprockets assist in this task.

United States Patent n 1 Schenck et al. I

[ 1 Jan. 30, 1973 (54] BENDING MACHINE [75] Inventors: Robert L. Schenck, York; George E. Schenck, Dallastown; Frank W. Senft, York, all of Pa.

[73] Assignee: Schenck Corporation, York, Pa.

[22] Filed: Aug. 25, 1971 [21] Appl. No.: 174,641

[52] US. Cl ..72/217 [5 l] Int. Cl. ..B2ld 7/024 [58] Field ofSearch ..72/216,215,2l7,2l8

[56] References Cited UNITED STATES PATENTS 2,396,l B2 3/1946 Kibler .;...72/2l7- 2,454,290 11/1948 Payne ..72/2l7 Primary Examiner-Milton S. Mehr Attorney-D. C. Roylance et al.

[ ABSTRACT A bending machine having a mandrel carrier, two axles passing through the carrier on a diameter thereof and mandrels mounted on the axles, there being a space between the closest points of the mandrels for the workpiece to pass through. Journals in a fixed frame are provided for the axles so that the carrier can be rotated about the axis of either axle. The carrier is provided with sprocket teeth about its periphery, and is rotated by a chain passing around the sprocket to form a shape generally like a U. The ends of the chain are attached to drive rods which are hydraulically moved to pull the chain and rotate the carrier in either direction. The journals are arcuate and open away from the drive rods, the action of the rods and chain being in a direction to keep one axle in continuous bearing contact with its associated journal. Guide sprockets assist in this task.

7 Claims, 3 Drawing Figures PATENIEDJAH30 I973 SHEET 1 [1F 2 v INVENTORS.

ROBERT L. SCHENCK GEORGE E. SCHENCK FRANK w SENFT e e6 e6 0 @u ATTORNEY3.

PAIENTEBJA QO ms 3.713317 sum 2 0F 2 IVNVENTORS. FIG. 3 ROBERT L. SCHENCK GEORGE E. SCHENCK FRANK w. SENFT ATTORNEYS.

BENDING MACHINE This invention relates to a bending machine and, more specifically, a drive mechanism fora machine for bending and forming elongated rod or bar stock.

In the construction industry it is highly desirable to be able to transport a machine for bending reinforcing rod and the like to a point of construction so that the rod can be delivered to the construction job in either straight rod or coil stock form and formed, as needed, into the various stirrup and other shapes usually required for reinforced concrete construction.

In copending U.S. Patent application Ser. No. l06,032, filed Jan. 13, 1971, there was disclosed a machine for accomplishing this task. As described therein, there are certain problems inherent in bending reinforcing rod. For one, it is necessary to be able to bend the rod in either direction and, further, when bending the rod it is desirable to maintain axes about which the rod is to be bent in a specific predetermined position. When doing so, as described with reference to the copending application, double mandrels can be used with the machine drive being designed to bend the pipe about the axis of either mandrel.

However, in so doing there are severe problems in maintaining the mandrels in their position relative to the starting point so that the axis about which the bend is being formed does not translate away from its starting position. In that application a key-lock mechanism was employed.

In accordance with the present invention, an improved bending machine includes double mandrels rotatable about the axis of either mandrel for bending elongated rod or bar stock, journal means for the axles of either of the mandrels, a mandrel carrier for supporting the axles of the mandrels and the mandrels themselves, and flexible drive means for rotating the mandrel carrier and for causing the rotation of the carrier and either mandrel axle about the axis of the other.

In order that the manner in which the foregoing is attained in accordance with the invention can be understood in detail, a particularly advantageous embodiment thereof will be described with reference to the accompanying drawings, which form a part of this specification, and wherein:

FIG. 1 is a side elevation, in partial section, of an apparatus in accordance with the invention;

FIG. 2 is a horizontal sectional view along lines 22 of FIG. 1; and

FIG. 3 is a partial side elevation of a portion of the apparatus of FIGS. 1 and 2 showing bending positions.

As will be seen in FIG. 1, the apparatus includes a main frame 5 which is shown in section and which is provided with a generally rectangular opening indicated at 6, through which the drive mechanism passes. Near one vertical edge of opening 6 there is provided a bearing block 7 which is provided with two v ertically'spaced arcuate bearing surfaces 9 opening away from frame 5. At the front of opening 6 frame 5 carries a second bearing block 8, seen in FIG. 2, block 8 being provided with similar arcuate bearing surfaces coaxially aligned with the bearing surfaces in block 7.

A mandrel carrier 10, which has a generally cylindrical shape, lies generally between blocks 7 and 8 and is provided with two axles 11 and 12, which extend completely through mandrel 10 on centers which are equally spaced from the central axis of the mandrel carrier and which lie on one diameter thereof. Rear stub portions of axles l 1 and 12 protrude from the back surface of the mandrel carrier and are dimensioned to mate with the arcuate bearing surfaces of block 7. The portions of axles 11 and 12 which protrude from the front surface of mandrel carrier 10 are provided with bushings and mandrels, axle 11 being provided with a bushing 14 and a mandrel l5, and axle 12 being provided with a mandrel 16. It will be observed that the bushings are provided with bearing surfaces and shoulders to mate with the arcuate recesses 9 in block 8 and that the shoulders on the bushings and at the rear surface of the mandrel carrier prevent significant axial movement of the carrier and its associated components with regard to frame 5.

The mandrel carrier is also provided with two substantially identical sprockets l7 and 18 which surround the mandrel carrier and are fixedly attached thereto.

Within the rectangular opening 6 in frame 5 is a bracket assembly 20 having front and rear plates with suitable bearing structures of conventional nature to support axles for a plurality of sprockets which are mounted on horizontal axes and which lie in the planes of the sprockets on mandrel carrier 10. Specifically, as

best seen viewing FIGS. 1 and 2 in conjunction, the sprockets are mounted in pairs, each pairhaving one sprocket aligned in a plane with sprocket l7 andthe other lying in the same plane as sprocket 18. Thus, sprockets 21 and 22 are aligned with sprockets 17 and 18, respectively, and are mounted on a common axle 23.'Similarly, sprockets 24 and 25 are aligned with sprockets 17 and 18, respectively, and are mounted on a common axle 26. Directly below those sprockets are similarpairs of which sprockets 27 and 28, mounted on axles 29 and 30, respectively, are visible. I

A pair of flexible link chains, 31 and 32, of a type generally referred to as bicycle chains, are passed around sprockets 17 and 18 on mandrel carrier 10 and between respective pairs of the sprockets supported in bracket 20. From the upper portion of mandrel carrier 10 the chains pass over sprockets 24 and 25 and under sprockets 21 and 22, while the portion of the chain attached to the bottom segment of mandrel carrier 10 passes under the sprockets supported on axle 30 and over the sprockets supported on axle 29. As will be seen in FIG. 2, the portions of the chains extending across the upper portion of mandrel carrier 10 and over sprockets 24 and 25 have been omitted to show the sprockets in plain view.

The distal ends of the upper portions of chains 31 and 32 are connected to a drive rod 35, and the ends of the lower portions of these chains are connected to a drive rod 36. Rod 35 passes through an opening in an upper portion of a mounting block 37 which is supported on frame 5 and which supports an hydraulic or ports 42 and 43. The mounting and other characteristics of the piston and cylinder arrangements are straightforward and conventional and need not be discussed in any detail.

In the operation of the above-described apparatus to bend a workpiece, the workpiece 50 is inserted between mandrelsIS and 16 in a direction perpendicular to the axes of the mandrels and also perpendicular to the plane in which the axes of the mandrels lie in their home or central position as shown in FIG. 1. Then, in order to produce a bend in an upward direction, fluid pressure is applied to port 39 of cylinder 38 while ports 40 and 42 are vented. The fluid pressure thus applied causes the piston within the cylinder 38 to move away from the mandrel carrier, pulling drive rod 35 to the left as shown in the figures. The upper portion of chain 32 is then pulled to to the left, causing portions of chains 31 and 32 to pass between the upper sprocket in the direction of cylinder 38. The chain in engagement with sprocket 17 and 18 causes the mandrel carrier to rotate in a counterclockwise direction as viewed in FIGS. 1 and 3, and as indicated by arrows 44. Axle 12 is caused to leave the bearing recess 9 and rotate about the axis of axle 11 which is retained in from bearing contact with its journal recess by the action of the chains pulling the mandrel toward block 7. 1

It will be observed that drive rod 36 necessarily moves to the right while drive rod 35 moves to the left. It is generally the case that port 42 can, be openly vented and that the fluid emerging from that vent will cause drive rod 36 to move slowly and maintain a minimum slack condition in the lower portion of the chain. However, it will also be recognized that athrottle vent can be used to cause a braking action in rod 36 to restrain the lower portion of the chain from becoming slack. Maintaining that portion of the chain taut, at least between the lower sprocket pair and the mandrel carrier, is important, because the lower portion of the chain assists in maintaining axle 11 in firm bearing engagement with its arcuate journal recess.

the motion of rod 35 and of the mandrel carrier is 7 continued, as shown in FIG. 3, until the desired amount of bend is attained in workpiece 50. Clearly, a bend of at least 180 can be attained. In order to produce a bend in the opposite direction it is simply necessary to apply fluid pressure to port 42, vent port 39 and move drive rod 36 to the left, causing the lower portion of the chain to induce clockwise rotation in the mandrel carrier and rotate the assembly about axle 12 to the position indicated in phantom lines at 46 in FIG. 3.

As will be seen, the idle sprockets maintain the chain between the drive rods and the mandrel carrier in proper position so that the selected one of axles 1 1 and 12 is maintained in engagement with its associated arcuaterecesses in blocks 7 and 8. Also, these sprockets prevent the chain from striking the surfaces of opening In orderto remove and replace the mandrel carrier it is simply necessary to vent ports 39 and 42, pull the carrier and the chain away from the bearing blocks until they are clear, and then disengagethe chains from sprockets 17 and 18. The replacement carrier is simply reengaged with the chain and restored to the position shown in FIG. LMandrels and carriers canbe quickly and easily substituted in this manner to enable the machine to bend rods of different sizes.

While one advantageous embodiment has been chosen to illustrate the invention it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.

What is claimed is:

1. A bending machine comprising the combination of first and second axles;

first and second mandrels carried respectively by said first and second axles; mandrel carrier means for supporting said first and second axles in parallel spaced relationship so that said mandrels are spaced apart by a distance at least as great as the thickness of a workpiece to be bent;

first and second semicircular bearing means for said first and second axles, respectively; means for inserting a workpiece between said mandrels andfor holding said workpiece in the inserted position; and

means for rotating said mandrel carrier means, said first axle and said first mandrel around the axis of said second axle to bend the workpiece in one direction, and for rotating said mandrel carrier means, said second axle and said second mandrelv around the axis of said first axle to bend the workpiece in the other direction, and

means for rotating including an elongated flexible drive element partially encircling and positively engaging said mandrel'carrier; and

means for pulling either end of said element to rotate said mandrel carrier about one of said axes.

2. A bending machine according to claim 1 wherein said drive element is a chain, and

said mandrel carrier is provided with means for mating in positive engagement with said chain.

3. A bending machine according to claim 1 wherein said means for pulling includes a piston and cylinder assembly connected to each end of said band, and means for conducting fluid under pressure to said cylinder.

4. A bending machine according to claim 1 wherein said drive element is a bicycle chain and said mandrel carrier is provided with sprocket teeth surrounding said carrier.

5. A bending machine according to claim 4 wherein said means for rotating further includes A plurality of idler sprockets, disposed between said mandrel carrier and said means for pulling, to guide said chain.

6. A bending machine comprising the combination of a mandrel carrier mounted for rotation and translation about either one of first and second axes;

first and second mandrels carried by said mandrel carrier and extendingfrom one face thereof,

said mandrels being mounted on said first and second axes which areparallel with each other,

said first and second axes being on one diameter of said mandrel carrier;

aligned with said one of said first and second axes in bearing relationship with said bearing means.

7. A bending machine according to claim 6 wherein said first and second mandrels include cylindrical surfaces, and

wherein the spacing between said first and second axes and the diameter of said mandrels are selected to provide a minimum distance between said mandrels which is slightly greater than'the diameter of the rod to be bent.

k l l 

1. A bending machine comprising the combination of first and second axles; first and second mandrels carried respectively by said first and second axles; mandrel carrier means for supPorting said first and second axles in parallel spaced relationship so that said mandrels are spaced apart by a distance at least as great as the thickness of a workpiece to be bent; first and second semicircular bearing means for said first and second axles, respectively; means for inserting a workpiece between said mandrels and for holding said workpiece in the inserted position; and means for rotating said mandrel carrier means, said first axle and said first mandrel around the axis of said second axle to bend the workpiece in one direction, and for rotating said mandrel carrier means, said second axle and said second mandrel around the axis of said first axle to bend the workpiece in the other direction, and means for rotating including an elongated flexible drive element partially encircling and positively engaging said mandrel carrier; and means for pulling either end of said element to rotate said mandrel carrier about one of said axes.
 1. A bending machine comprising the combination of first and second axles; first and second mandrels carried respectively by said first and second axles; mandrel carrier means for supPorting said first and second axles in parallel spaced relationship so that said mandrels are spaced apart by a distance at least as great as the thickness of a workpiece to be bent; first and second semicircular bearing means for said first and second axles, respectively; means for inserting a workpiece between said mandrels and for holding said workpiece in the inserted position; and means for rotating said mandrel carrier means, said first axle and said first mandrel around the axis of said second axle to bend the workpiece in one direction, and for rotating said mandrel carrier means, said second axle and said second mandrel around the axis of said first axle to bend the workpiece in the other direction, and means for rotating including an elongated flexible drive element partially encircling and positively engaging said mandrel carrier; and means for pulling either end of said element to rotate said mandrel carrier about one of said axes.
 2. A bending machine according to claim 1 wherein said drive element is a chain, and said mandrel carrier is provided with means for mating in positive engagement with said chain.
 3. A bending machine according to claim 1 wherein said means for pulling includes a piston and cylinder assembly connected to each end of said band, and means for conducting fluid under pressure to said cylinder.
 4. A bending machine according to claim 1 wherein said drive element is a bicycle chain and said mandrel carrier is provided with sprocket teeth surrounding said carrier.
 5. A bending machine according to claim 4 wherein said means for rotating further includes A plurality of idler sprockets, disposed between said mandrel carrier and said means for pulling, to guide said chain.
 6. A bending machine comprising the combination of a mandrel carrier mounted for rotation and translation about either one of first and second axes; first and second mandrels carried by said mandrel carrier and extending from one face thereof, said mandrels being mounted on said first and second axes which are parallel with each other, said first and second axes being on one diameter of said mandrel carrier; means for delivering a portion of rod to be bent to a position between said mandrels and for holding said rod in said position; first and second axles extending from said mandrel carrier along said first and second axes, respectively; substantially semicircular bearing means for said axles; and means for rotating said mandrel carrier about one of said first and second axes and for retaining the selected one of said first and second axles which is aligned with said one of said first and second axes in bearing relationship with said bearing means. 